Reduction in energy expenditure after liver transplantation

After successful liver transplantation (LTx), excessive weight gain is comm on among recipients. This rapid change in body morphology has been attribut ed to immunosuppressive regimens. The liver's role as a metabolic sensor an d its autonomic innervation are pivotal in relaying humoral and neural info rmation to the hypothalamus, where ingestive behavior is determined and has largely been ignored. We examined and assessed the contribution of drugs, energy intake, and energy expenditure on weight gain after LTx. Twenty-thre e patients were followed up at 3-mo intervals after LTx. Energy expenditure was measured by indirect calorimetry and dietary intake by diet diaries, a nd body composition was assessed with anthropometry and multifrequency bioe lectrical impedance analysis. Cumulative drug doses were calculated, and as sociations between body composition and immunosuppressive regimens and ener gy expenditure were examined. Nine months after LTx, 20 of 23 (87%) recipie nts were overweight or obese, despite three-fourths of this cohort being on weight-reduction regimens. After LTx. a decrease in measured energy expend iture was observed (60.3 +/- 1.6 kJ/kg of body cell mass pre-LTx versus 53. 7 +/- 2.3 kJ/kg of body cell mass after 9 mo; P < 0.05). Multiple stepwise regression analysis showed that, when adjusted for body weight, the stronge st predictor of fat mass at 9 mo after LTx was resting energy expenditure. Weight gain after LTx is not predicted by immunosuppressive drug dosage. Th e strong association between weight gain and energy economy might be a cons equence of the loss of hepatic metabolic integration and accelerated furthe r by increased energy intake. Effective management of weight gain will not be achieved until the mechanisms involved in altered energy homeostasis are elucidated. (C) Elsevier Science Inc. 2001.